1. Chapter 6 Skin and the Integumentary System
Composed of several tissues
Maintains homeostasis
Protective covering
Retards water loss
Regulates body temperature
Houses sensory receptors
Contains immune system cells
Synthesizes chemicals, including Vitamin D
Excretes small amounts of waste

2. Layers of Skin
Epidermis
Dermis
Subcutaneous layer

3. Epidermis, Dermis, & Basement Membrane
Epidermis is subdivided into layers of stratified squamous epithelium
Dermis is made up of connective tissue, epithelial tissue, smooth muscle tissue, nervous tissue, and blood.
Basement membrane is anchored to the dermis by short fibrils and separates these two layers of skin

4. Epidermis lacks blood vessels keratinized
thickest on palms and soles ( mm)
melanocytes provide melanin
rests on basement membrane
stratified squamous

5. Epidermis Layers of Epidermis stratum corneum stratum lucidum
stratum granulosum
stratum spinosum
stratum basale

7. Layers of the Epidermis

8. Skin Changes: Rashes

9. Chicken Pox
Shingles
Impetigo
Lyme Disease

10. Melanocytes and Pigment Granules

11. All people have the same number of melanocytes in their skin

12. Albinism: Lack of Melanin

13. Paul Bettany in Columbia Pictures' The Da Vinci Code - 2005
THE ALBINO MONK?

14. Dermis on average 1.0-2.0mm thick dermal papillae
binds epidermis to underlying tissues
irregular dense connective tissue
muscle cells
nerve cell processes
blood vessels
hair follicles
glands

16. Subcutaneous Layer hypodermis loose connective tissue adipose tissue
insulates
major blood vessels

17. Hair Follicles epidermal cells tube-like depression
extends into dermis
hair root
hair shaft
hair papilla
dead epidermal cells
melanin
arrector pili muscle

20. EXAMPLES OF HAIR COLOR VARIATION
Grey’s Anatomy
With age, a loss of melanin in hair can lead to grayness.
EXAMPLES OF HAIR COLOR VARIATION
Red Heads have iron pigment (trichosiderin)
Everyone except albinos have various amounts of melanin in their hair.

21. Nails
protective coverings
nail plate
nail bed
lunula
6-9

22. Sebaceous Glands usually associated with hair follicles
holocrine glands – disintegrating cell and its contents for the secretion
secrete sebum
absent on palms and soles

24. Sweat or Sudoriferous Glands
widespread in skin
deeper dermis or hypodermis
eccrine glands – types of merocrine gland that secrete fluid (sweat) product released through the cell membrane
aprocrine sweat, ceruminous (wax), & mammary (milk) glands – types of aporocrine glands that secrete cellular product and portion of the free ends of cells

26. Regulation of Body Temperature

28. Problems in Temperature Regulation
Hyperthermia – abnormally high body temperature
Human Body Temperature = 37o C or 98.6o F.
Hypothermia – abnormally low body temperature

29. Skin Color Genetic Factors Physiological Factors varying amounts of
melanin
varying size of melanin
granules
albinos lack melanin
Physiological Factors
dilation of dermal blood vessels
constriction of dermal blood vessels
carotene
jaundice
Environmental Factors
sunlight
UV light from sunlamps
X rays
George Hamilton – sun worshiper?

30. The Tan Man at The University of Kansas

31. Healing of Cuts

34. Healing of Burns
First degree burn – superficial partial-thickness (epidermis damaged)
Second degree burn – deep partial-thickness (epidermis & dermis damaged)
Third degree burn – full-thickness (epidermis, dermis, & accessory skin structures)
autograft (self-transplant)
homograft (temporary transplant from donor)
various skin substitutes
extensive scars

35. Rule of Nines

36. Life Span Changes Melanin production slows Scaly skin Hair thins
Number of hair follicles decrease
Impaired nail growth
Sensory receptors decline
Inability to control body temperature
Less vitamin D production
Scaly skin
Age spots
Dermis becomes reduced
Loss of fat
Wrinkles
Sagging
Sebaceous glands secrete less oil

37. Life Span Changes - Skin

38. Clinical Application Acne Vulgaris most common skin disorder
sebum and epithelial cells clog glands
produces whiteheads and blackheads (comedones)
anaerobic bacteria trigger inflammation (pimple)
largely hormonally induced
androgens stimulate sebum production
treatments include antibiotics, topical creams, birth control pills

40. Common Skin Disorders
Athlete’s foot – tinea pedis or ringworm fungal infection of the foot.
Birthmark – congenital blemish or spot on the skin.
Boil – bacterial infection of the skin produced when bacteria enter a hair follicle.
Carbucnle – bacterial infection, similar to a boil, that spreads into the subcutaneous tissues.
Cyst – fluid-filled capsule.
Eczema – noncontagious skin rash.
Erythema – reddening of the skin due to dilation of dermal blood vessels in response to injury or inflammation.
Herpes– characterize by a recurring formations of small clusters of vesicles; usually caused by herpes simplex virus; contagious.
Keloid – elevated enlarging fibrous scar usually initiated by an injury.
Mole – fleshy skin tumor that is usually pigmented.
Pediculosis – disease produced by an infestation of lice.
Pruritus – itching of the skin.
Pusule – elevated, pus-filled area.

41. Xeroderma Pigmentosum
Extreme freckling and skin cancer due to lack of DNA repair enzymes.

42. Types of Skin Cancer
Squamous cell carcinoma – derived from epithelial tissue
Basal cell carcinoma – derived from epithelial tissue
Malignant melanoma – derived from melanocytes